diff --git a/tests/apitests/python/test_robot_account.py b/tests/apitests/python/test_robot_account.py
index 5a6a7c7b6..9c78abbbe 100644
--- a/tests/apitests/python/test_robot_account.py
+++ b/tests/apitests/python/test_robot_account.py
@@ -71,7 +71,7 @@ class TestProjects(unittest.TestCase):
         image_project_a = "haproxy"
         image_project_b = "hello-world"
         image_project_c = "httpd"
-        image_robot_account = "mariadb"
+        image_robot_account = "alpine"
         tag = "latest"
 
         print "#1. Create user(UA);"
diff --git a/tests/ci/api_common_install.sh b/tests/ci/api_common_install.sh
index c4a3b2b04..cf70de1c1 100755
--- a/tests/ci/api_common_install.sh
+++ b/tests/ci/api_common_install.sh
@@ -4,6 +4,7 @@ set -x
 set +e
 sudo rm -fr /data/*
 sudo mkdir -p /data
+docker system prune -a -f
 DIR="$(cd "$(dirname "$0")" && pwd)"
 
 set -e
diff --git a/tests/ci/api_run.sh b/tests/ci/api_run.sh
index 7f6c043b5..393c3f058 100755
--- a/tests/ci/api_run.sh
+++ b/tests/ci/api_run.sh
@@ -28,10 +28,13 @@ function uploader {
 set +e
 
 docker ps
-
+# Log storage space before running API_DB.robot
+df -H
 # run db auth api cases
 if [ "$1" = 'DB' ]; then
     pybot -X -v ip:$2 -v HARBOR_PASSWORD:Harbor12345 $DIR/../../tests/robot-cases/Group0-BAT/API_DB.robot
+    # Log storage space after running API_DB.robot
+    df -H
 elif [ "$1" = 'LDAP' ]; then
     # run ldap api cases
     python $DIR/../../tests/configharbor.py -H $IP -u $HARBOR_ADMIN -p $HARBOR_ADMIN_PASSWD -c auth_mode=ldap_auth \
diff --git a/tests/robot-cases/Group0-BAT/API_DB.robot b/tests/robot-cases/Group0-BAT/API_DB.robot
index 4288c1561..59d28b876 100644
--- a/tests/robot-cases/Group0-BAT/API_DB.robot
+++ b/tests/robot-cases/Group0-BAT/API_DB.robot
@@ -18,54 +18,80 @@ ${SERVER_API_ENDPOINT}  ${SERVER_URL}/api
 
 *** Test Cases ***
 Test Case - Garbage Collection
+    [Tags]  gc
     Harbor API Test  ./tests/apitests/python/test_garbage_collection.py
 Test Case - Add Private Project Member and Check User Can See It
+    [Tags]  private_member
     Harbor API Test  ./tests/apitests/python/test_add_member_to_private_project.py
 Test Case - Delete a Repository of a Certain Project Created by Normal User
+    [Tags]  del_repo
     Harbor API Test  ./tests/apitests/python/test_del_repo.py
 Test Case - Add a System Global Label to a Certain Tag
+    [Tags]  global_lbl
     Harbor API Test  ./tests/apitests/python/test_add_sys_label_to_tag.py
 Test Case - Add Replication Rule
+    [Tags]  replic_rule
     Harbor API Test  ./tests/apitests/python/test_add_replication_rule.py
 Test Case - Edit Project Creation
+    [Tags]  pro_creation
     Harbor API Test  ./tests/apitests/python/test_edit_project_creation.py
 Test Case - Manage Project Member
+    [Tags]  member
     Harbor API Test  ./tests/apitests/python/test_manage_project_member.py
 Test Case - Project Level Policy Content Trust
+    [Tags]  content_trust
     Harbor API Test  ./tests/apitests/python/test_project_level_policy_content_trust.py
 Test Case - User View Logs
+    [Tags]  view_logs
     Harbor API Test  ./tests/apitests/python/test_user_view_logs.py
 Test Case - List Helm Charts
+    [Tags]  list_helm_charts
     Harbor API Test  ./tests/apitests/python/test_list_helm_charts.py
 Test Case - Assign Sys Admin
+    [Tags]  assign_adin
     Harbor API Test  ./tests/apitests/python/test_assign_sys_admin.py
 Test Case - Copy Artifact Outside Project
+    [Tags]  copy_artifact
     Harbor API Test  ./tests/apitests/python/test_copy_artifact_outside_project.py
 Test Case - Robot Account
+    [Tags]  robot_account
     Harbor API Test  ./tests/apitests/python/test_robot_account.py
 Test Case - Sign A Image
+    [Tags]  sign_image
     Harbor API Test  ./tests/apitests/python/test_sign_image.py
 Test Case - Project Quota
-   Harbor API Test  ./tests/apitests/python/test_project_quota.py
+    [Tags]  quota
+    Harbor API Test  ./tests/apitests/python/test_project_quota.py
 Test Case - System Level CVE Whitelist
+    [Tags]  sys_cve
     Harbor API Test  ./tests/apitests/python/test_sys_cve_whitelists.py
 Test Case - Project Level CVE Whitelist
+    [Tags]  pro_cve
     Harbor API Test  ./tests/apitests/python/test_project_level_cve_whitelist.py
 Test Case - Tag Retention
+    [Tags]  tag_retention
     Harbor API Test  ./tests/apitests/python/test_retention.py
 Test Case - Health Check
+    [Tags]  health
     Harbor API Test  ./tests/apitests/python/test_health_check.py
 Test Case - Push Index By Docker Manifest
+    [Tags]  push_index
     Harbor API Test  ./tests/apitests/python/test_push_index_by_docker_manifest.py
 Test Case - Push Chart By Helm3 Chart CLI
+    [Tags]  push_chart
     Harbor API Test  ./tests/apitests/python/test_push_chart_by_helm3_chart_cli.py
 Test Case - Push Cnab Bundle
+    [Tags]  push_cnab
     Harbor API Test  ./tests/apitests/python/test_push_cnab_bundle.py
 Test Case - Create/Delete tag
+    [Tags]  tag_cuid
     Harbor API Test  ./tests/apitests/python/test_create_delete_tag.py
 Test Case - Scan Image
+    [Tags]  scan
     Harbor API Test  ./tests/apitests/python/test_scan_image_artifact.py
 Test Case - Scan All Images
+    [Tags]  scan_all
     Harbor API Test  ./tests/apitests/python/test_system_level_scan_all.py
 Test Case - Registry API
+    [Tags]  reg_api
     Harbor API Test  ./tests/apitests/python/test_registry_api.py